1. L. COLEMAN 2011

2. GENE: the section of a DNA molecule that contains the recipe for one protein. NOTE: Each DNA molecule with it’s supporting structures Is called a CHROMOSOME.

3. 1.A Mutation is defined as: A change in the base sequence of a DNA molecule. Point mutation Inversion Deletion. Can be devastating because it changes everything that follows it. THE FAT CAT ATE THE RAT X TEF ATC ATA TET HER AT becomes:

4. 2. Mutations are most likely to happen: During DNA replication because nucleotides are moving into position and not yet bonded together.

5. 3. The effect of a mutation on the function of a gene depends on: How it changes the amino acid sequence and how that change affects the structure and function of the protein. 4. Once a mutation occurs it will be passed on to: All cells descending (by cell division) from the mutated cell - because when DNA replicates it copies the mutation too.

6. 5. The effect of a mutation on an organism depends on: a.How it affects the function of the protein AND what the protein did for the organism - may have no effect, in rare cases may be beneficial, usually harmful. b.What kind of cell has the mutation. c.Developmental stage of the organism. 1.Worst is fetal development - all subsequent cells have the mutation. 2.In adults can result in out-of-control cell division, aka CANCER. 6. Beneficial mutations are why evolution occurs. Without them There could be no natural selection.

7. 7. Mutations are passed from parents to offspring only if: they occur in sperm or egg cells (in sexually reproducing organisms). 8. Mutations can happen as a matter of chance during replication. The probability of a chance mutation occurring when DNA replicates is: 1 mutation/100,000 genes

8. 9. Anything that can penetrate the nucleus of a cell and interfere with the replication process greatly increases the probability of mutation occurring. Such mutation-causing agents are called mutagens and/or carcinogens. Some examples are: a.Radiant energy stronger than visible light: 1)UV radiation 2)X-Ray 3)Gamma radiation (radioactivity)

9. b. Viruses

10. c. Chemicals 1) environmental toxins 2) drugs (prescription or otherwise): nicotine, alcohol, cocaine etc.